<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    jq_02/05.echo.html
    <script>
        $(function () {
            $('#btn1').bind('click',function () {
                console.log(1);
            })
            var $btn2 = $('#btn2');
            $btn2.click(function () {
                console.log(2);
            })
            $btn2.click(function () {
                console.log(22);
            })
            $('.mybtn').click(function () {
                console.log(34);
            })
            $('#btn5').click(function () {
                console.log(this);
                console.log($(this));
            })

        })
    </script>
</head>
<body>
    <button id="btn1">btn1</button>
    <button id="btn2">btn2</button>
    <button id="btn3" class="mybtn">btn3</button>
    <button id="btn4" class="mybtn">btn4</button>
    <button id="btn5">btn5</button>
    <button id="btn6">btn6</button>
    <button id="btn7">btn7</button>
    <button id="btn8">btn8</button>
    <button id="btn9">btn9</button>
</body>
</html>